InChI=1S/C17H17NO7S/c19-14-6-1-12(2-7-14)3-10-17(21)18-11-16(20)13-4-8-15(9-5-13)25-26(22,23)24/h1-10,16,19-20H,11H2,(H,18,21)(H,22,23,24)/b10-3+